Question

why is acid rain harmful to marble and limestone structures ? use your know knowledge of the reactions ?

Answer 1

Answer. Due to pollution, oxides of nitrogen and sulphur are quite rich in the atmosphere.

The prominent oxides of nitrogen are nitrogen dioxide and nitrate and of the sulphur are sulphur dioxide and sulphate.

When water reaches the earth surface in the form of rain it combines with these oxides to form nitrous acid if cimbines with NO2, nitric acid if cimbines with NO3, sulphuric acid when water combines with sulphate etc.

These acids formed in the atmosphere when fall on monument surface made up of limestone, it leads to the corrosion of the former.

This happens because acid combines with calcium carbonate to form gypsum, and then it is lost in the form of powder.